Is testing for inherited coagulation inhibitor deficiencies in young stroke patients worthwhile?

Objective. To test the hypothesis that in patients under age 50, with a first, arterial, ischemic cerebral infarct, whose family history and medical history do not suggest an inherited coagulation inhibitor deficiency, the yield of a laboratory search for these disorders will be low. Materials and methods. In 55 such patients under age 50, we systematically searched for deficiencies of protein C, protein S, and antithrombin III. Results. No abnormalities of protein C or antithrombin III were found. One patient had a deficiency of protein S, which was most likely acquired rather than inherited. Conclusions. In patients who lack clinical features of a prothrombotic state, the yield of testing for protein C, S and AT III deficiency is likely to be low.